Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6597af1e4d3f0fd…

MALICIOUS

PDF

83.6 KB Created: 2021-09-02 09:30:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1644efaec996ff5bb13a37cf13627911 SHA-1: bea0367aef2791545a9de2ef99ccb000840ac6ab SHA-256: a6597af1e4d3f0fd9396e79d0a1774a3d0c58d6772e5a2d73a12cb3de3e0afa4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with numerous URLs pointing to compromised CMS uploads and disposable hosting. These links likely serve as lures for phishing or to distribute further malware, aligning with the 'Malicious Link' technique.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://investainternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609faebc07c11---bunupulur.pdf
    • https://spacio.hk/attachment/file/pukaviwalitonufemawuwabi.pdf
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c64b69aa525---42024153668.pdf
    • https://salvamontbihor.ro/app/webroot/files/userfiles/files/sebatamage.pdf
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/e18aa65e278f066597fd70f37ce217d2/61065695002.pdf
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160c8d61fe61b8---51647377897.pdf
    • http://zakuskymoser.cz/www/ckfinder/userfiles/files/7665265093.pdf
    • https://flvirginia.com/wp-content/plugins/super-forms/uploads/php/files/c2f626077a26771d50e71d588f5d32b9/xuwezomedikawe.pdf
    • https://cursosgratuitosonline.es/wp-content/plugins/super-forms/uploads/php/files/r41ftr5rvs9htiobe7uv6p4aqt/67599517580.pdf
    • https://empylean.com/wp-content/plugins/super-forms/uploads/php/files/bi1pjnhhp201fu9j8pk79osk0p/jolexisebuwufetipilutu.pdf
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/16083416445d0f---tinubezalikegidi.pdf
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f2a719a34b---xubusomuxaxub.pdf
    • http://ordinate-ltd.com/file_media/file_image/file/16195969170.pdf
    • https://www.prowallpanama.com/wp-content/plugins/super-forms/uploads/php/files/3312d441f05a6798f6efb9726e1b58aa/25772605390.pdf
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1609b98b421ca5---basesejanugexibalumada.pdf
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080202778224---supixipiru.pdf
    • http://fujavietnam.com/images/Download/58540082604.pdf
    • https://majorsagilekvaros.hu/uploads/file/67138398657.pdf
    • https://kuepancong.com/contents//files/wuzutubifi.pdf
    • http://reszke.pl/fckeditor/editor/filemanager/connectors/php/file/7511665354.pdf
    • https://betalinktech.com/blmedia/file/82300474191.pdf
    • http://lulanjina.net/upload/files/dewemososut.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=strongest+characters+in+injustice+2
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e152.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE152 16792 bytes
font_01_sfnt_off0000f969.bin
525ecd994feb7809b44c744a20c60c7d9345d7fb0a49b6a77fe1ea58c185c36c
pdf-font-stream PDF embedded font (sfnt) at offset 0xF969 10888 bytes
font_02_sfnt_off00011287.bin
2da2cae1f37c45d4a25353e53ae035b35f434daacbf2961d989f62d63957ef25
pdf-font-stream PDF embedded font (sfnt) at offset 0x11287 17732 bytes